code: def test_metrics_arguments(self):
      series00 = self.series0.stack(self.series0)
      series11 = self.series1.stack(self.series1)
      assert (
          metrics.r2_score(series11, series00, True, reduction=np.mean)
          == 0
      )
      assert (
          metrics.r2_score(series11, series00, reduction=np.mean) == 0
      )
      assert (
          metrics.r2_score(
              series11, pred_series=series00, reduction=np.mean
          )
          == 0
      )
      assert (
          metrics.r2_score(
              series00, actual_series=series11, reduction=np.mean
          )
          == 0
      )
      assert (
          metrics.r2_score(
              True,
              reduction=np.mean,
              pred_series=series00,
              actual_series=series11,
          )
          == 0
      )
      assert (
          metrics.r2_score(
              series00, True, reduction=np.mean, actual_series=series11
          )
          == 0
      )
      assert (
          metrics.r2_score(
              series11, True, reduction=np.mean, pred_series=series00
          )
          == 0
      )
  
      # should fail if kwargs are passed as args, because of the "*"
      with pytest.raises(TypeError):
          metrics.r2_score(series00, series11, False, np.mean)
  
imports: import numpy
  import pandas
  import pytest
  from darts import TimeSeries
  from darts.metrics import metrics
label_desc: Use image node_id 22 for calling the TestMetrics obj's underlying member method code with example usage: obj.test_metrics_arguments() without return types